The use of bipolar electrodes for insertion into the ventricular cavity for the purpose of restarting the heart function by the transmission thereto of electrical impulses is well known. Such bipolar electrode pairs may comprise a flexible inner conductive element and a flexible outer conductive element fabricated from an extremely flexible and resilient coil spring with an insulating element disposed between the flexible inner and outer conductors and with the outer conductive element having a bend in the form of an elbow at one end thereof. Such a bipolar electrode is disclosed in my previous U.S. Pat. No. 3,516,412. In such a prior art arrangement, the bipolar electrode pair is inserted into the ventricular cavity by puncturing the chest wall and the wall of the heart muscle with a needle. The needle in such a prior art arrangement may comprise a cylindrical sheath or sleeve through which a substantially rigid pointed stylet is inserted to achieve puncture without clogging of the sleeve portion. After puncture is achieved, the stylet portion is withdrawn and the bipolar electrode pair inserted through the sleeve portion into the ventricular cavity with the sleeve then being withdrawn so as to leave the bipolar electrode pair in place. In prior art arrangements prior to my U.S. Pat. No. 3,516,412 attending physicians could not readily determine whether proper electrical contact was being achieved inside the cavity. The invention disclosed in my previous U.S. Pat. No. 3,516,412 overcomes this problem of the prior art by providing a linear irregularity close to the end of the bipolar electrode pair which is inserted into the ventricular cavity so as to increase the drag on the electrode as it passes through the sleeve of the inserting needle. This drag ceases abruptly when the portion of the electrode at which the irregularity is located passes out of the needle sleeve. In such an arrangement, simply removing the sleeve portion of the needle places the distal end of the stylet against the endocardium automatically. Moreover, in the arrangement disclosed in my previous U.S. Pat. No. 3,516,412, the cessation of the frictional drag resulting from the linear irregularity exiting the cannula of the needle enables a portion of the bipolar electrode pair between the distal end and the linear irregularity to automtically return to its unbiased or unstressed condition in which an angle is subtended between that portion and the rest of the stylet so as to automatically place the distal end of the stylet against the endocardium.
Although my previous patented arrangement disclosed in U.S. Pat. No. 3,516,412 overcomes several of the problems of the prior art, it still requires the attending physician to first insert the needle into the heart, then remove the inner stylet, thereafter pass the electrode into the sleeve portion, only being able to ascertain or verify entry into the heart by the presence of the aforementioned frictional drag after the bipolar electrode pair has been passed through the inner needle into the patient. Moreover, this arrangement does not readily provide for insertion of a heart stimulating fluid, such as Epinephrin if its use is also desired by the attending physician to assist in restarting the heart function, thus requiring a separate needle puncture or injection. Since in the event of a cardiac arrest time is of the essence, it would be most desirable for the attending physician to have the immediate option of injecting a heart stimulating fluid as well as inserting a bipolar electrode pair with a minimum of effort and time in situations where seconds could mean a patient's life. The prior art, moreover, has been found to be clumsy, especially in emergency situations such as those requiring external chest massage.
These disadvantages of the prior art are overcome by the present invention.